


A Future In Ruins

by Isobel_Morgan



Category: Doctor Who (2005)
Genre: Gen, OC Companion, Post-Fam Thirteen, Special Guest Stars in Chapters 3 and 4, Spoilers
Language: English
Status: Completed
Published: 2020-11-26
Updated: 2020-11-29
Packaged: 2021-03-09 19:15:20
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 20,726
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27691244
Author URL: https://archiveofourown.org/users/Isobel_Morgan/pseuds/Isobel_Morgan
Summary: The Thirteenth Doctor and her latest friend explore some ancient alien ruins, and get stuck in an impossible trap.Follows on from 'Anamnesis'.
Kudos: 3





	1. Chapter 1

The TARDIS was in flight, and the Doctor and Serene were practising the waltz around the console when the alert first sounded.

"Wait, am I leading or are you?" the Doctor asked, pausing mid-turn.

"I've no idea!" Serene replied, bumping into her and trying not to laugh. "I think we're both doing our own thing and it just happens they're lining up."

"Huh. That probably happens a lot."

The alert sounded again, louder this time, and the Doctor let go of Serene, who continued to waltz on her own, humming a tune in time.

"Should check out what that noise is."

The Doctor found the flashing light that indicated an incoming message - a set of coordinates, but nothing else.

"Hmm. Someone being deliberately cryptic, or a trap?"

Serene stopped waltzing, attention caught.

"Do people often send you messages as a trap?"

"Sometimes. Usually there's a bit more to it than a set of coordinates. But then it's pretty well known I can't resist a mystery…"

And she couldn't. Her fingers were itching to be off, to investigate what this was about.

"Does that count as a mystery?" Serene asked. "It could just be advertising."

"Let's have a look."

The Doctor input the coordinates, and on screen it showed a small green planet within a spiral galaxy, surrounded by other planets.

"Ooh. Haven't been there in ages."

"Where?" Serene asked.

"Rhyolae. In the Kjadi system."

The image zoomed in.

"Somewhere on the continent of Itera, by the looks of it."

Serene's face lit up with delight.

"Wait, Itera on Rhyolae? That's where the Isenal civilisation was! The ruins of the whole city of Laniyah still stand, and the modern culture on Rhyolae have this huge organisation, the Keepers, dedicated to preserving them. Please tell me we're going there?"

The Doctor raised her eyebrows, amused.

"Guessing you don't think it's a trap anymore?"

"So long as I get to see the ruins, I don't care! I can't believe I haven't asked to see them before - I spent years reading about them and the Isenal!"

The Doctor couldn't help but smile at Serene's enthusiasm. She'd been a little concerned that Serene's experiences on Ksako might have had a serious effect on her, but she seemed to be coping.

"Better check it out, then."

The Doctor threw the lever, and they were off.

Opening the doors, they found themselves right in the middle of the ruins of Laniyah, the city of the Isenal.

"Wow!"

Serene was ecstatic.

"That's the Elevation Temple! We're in the Confluence."

Almost the entire ancient city survived, built around the enormous stepped pyramid and its enclosed courtyard. The walls were high, but any roofing was long gone, leaving the ruins open to the lilac sky. The jungle had moved in, growing up over the walls. Creepers made long arms inside the structures, green tendrils wrapping themselves around the ceiling columns that now held up nothing.

The orange sun was high in the sky, and it was uncomfortably warm, but very beautiful. The Doctor slipped on her sunglasses, looking around but there was no sign of who'd summoned her there or, at that moment, of anyone at all, only a few lizard-like creatures skittering by, some brightly coloured birds flitting through the sky, making weird cries.

Serene was drawn to the bright flowers growing along the wall beside them. Each bloom was the size of her own face, the petals shades of pink and purple, and the pollen in the centre a vivid yellow.

"These are beautiful!"

The Doctor glanced over.

"Uh, don't get too close. And watch where you put your feet."

"Why?"

"Because they're Venandi blooms. They hunt by entangling prey in their creepers."

"Hunt?!"

Serene snatched her hand back. As she tried to step away, one of the tendrils snapped around her ankle, digging sharp thorns into her flesh.

"Doctor!"

"Hold still."

The Doctor hurried over, trying different frequencies on the sonic to try and convince the vine to let go.

"Do… do they hunt people?"

"Depends on what wanders past, I s'pose."

Serene tried not to panic.

"You don't seem worried, but there's a plant that might want to eat me growing around my leg?"

"They can take up to a couple of weeks to fully digest their prey, so we've got plenty of time. Unless… what season would you say it was?"

"I've no idea," Serene replied. "Summer maybe, with all these blooms?"

"They get more aggressive in late autumn, when food gets more scarce. They can overwhelm victims in under a minute."

Another flowering tendril began to crawl towards them, then another, until they were more or less surrounded.

"Doctor?"

Panic was definitely setting in now.

"I know I wanted to come here, but I was hoping to have more than two minutes before I got devoured by a plant?"

"Nearly there…"

The Doctor tried one more setting, and there was a tiny shrill scream from the tendril.

"Well, don't try and eat my friend, then!" The Doctor told it. "Let go, and I won't have to do that again."

Sulkily, the plant began to retract its tendrils, but it had wrapped so thoroughly around Serene's ankle, it chose to detach that part of itself, rather than untangle itself. She stepped away, carefully.

"Is this going to come off?"

"Eventually. Don't worry about it too much, it's part of how they reproduce."

"What?!"

"I mean, they use whatever passes by to distribute their pollen. It'll drop off when it's ready. You okay?"

"I think so. I wasn't expecting the local flora to be quite so… predatory."

"At least you know what to look out for now. General advice when exploring new places; watch where you step, and don't touch anything."

"I know. The temples and burial sites have booby traps too. The Keepers have spent generations deterring tomb robbers, and all archaeologists, anyone who wants to study the ruins, is carefully vetted. It isn't easy to get a permit either."

That struck a chord with the Doctor.

"So… why did the coordinates bring us right into the middle of the ruins?" she asked, taking another look around.

"I'm pretty sure I know who sent them, but they should be here, or someone should. Thought there'd at least be a message."

"Do you know many archaeologists?" Serene asked.

"One or two."

Keeping a careful eye where she stepped, the Doctor went over to the stone columns set in the centre of the Confluence, investigating the pictograms carved all around them. The TARDIS took longer to translate the written word, but she realised these were stories of how the temple came to be built, the deities worshipped there, and, she realised with some embarrassment, included a story of the last time she'd visited.

"Whoops. Forgot about how that worked out. They got the chin right, though, and the fez is a nice touch. Don't know if Amy'd be happy with the way they drew her, but they did put her down as a god as well, so there's that."

She traced a fingertip across the glyph of the TARDIS.

"Wonder how many times you turn up on things like this? How many mythologies are there built around a magical blue box?"

Serene was reading a different inscription, on the back of a low stone plinth located just before the stepped temple itself.

"Doctor? I can read most of the carvings, but this isn't translating?"

"That's weird."

The Doctor joined her, taking off her sunglasses, and what she saw made her take a sharp in-breath.

"That's because the TARDIS doesn't translate written Gallifreyan."

"Gallifreyan?" Serene glanced at the Doctor, worried by her expression, then looked back at the symbols. "What does it say?"

"Hello Sweetie."

The Doctor spun around, rapidly looking all over the ruins, hearts beating hard.

"She was here. River."

"River?"

That revelation didn't make Serene any less concerned.

"She's the one who called us here?"

"Uh huh. She does this when she wants to get my attention, or she used to."

Serene accepted that. When some of the Doctor's memories had merged with her own, she'd gained insight toward parts of the Doctor's life, and that meant she didn't have to ask certain questions. Most of those memories had been removed, but traces lingered. She wanted to ask more about the Doctor's wife, but also knew how painful a subject it was, and that made her hesitate.

"I haven't seen her since I regenerated," the Doctor continued.

Serene thought that over.

"So… she's only ever known you as a man? Will that matter?"

"Not to her. Or to me. It'll just be… different."

_'Is that nerves?'_ The Doctor thought. _'Excitement? Or just worry that I'll be awkward this time around?'_

Serene looked at the Gallifreyan inscription again, recognising the similarity to the symbols inside the TARDIS, briefly wondered what those said, whether she'd ever learn to translate them. Then she realised something else.

"But this must have been carved thousands of years ago?" she asked. "Does that mean she was only here then?"

"Maybe. The coordinates didn't specify the exact date, but usually when River contacts me, the TARDIS brings me to the right time."

Serene moved around the plinth, searching for anything that wasn't the Isenal pictograms, and found a large flat stone set into the ground.

"There's more here, Doctor. It doesn't look as old."

The Doctor knelt beside her - it was true, these Gallifreyan symbols, though weathered, weren't as badly worn as the others. She read them slowly, taking it in.

"I missed her. She came here twice, no, three times, and I missed her every time."

"What does it say?"

"Uh… some of it's private. Probably should be left untranslated."

The Doctor found she was blushing a little. River had clearly come from a part of her timeline after their relationship was a bit more… physical. Probably after they'd married.

"She came here looking for something. Probably an artefact, stealing to order, or to win an argument. She was a Professor of Archaeology, and sometimes she liked to travel back in time and take whatever she needed to prove she was right about long-dead cultures."

"I'm sure every archaeologist would like to do that, if they could," Serene replied, smiling.

"She also liked to annoy people," The Doctor continued. "Especially if she thought they were boring, or took things too seriously. I'm not sure what she meant here…"

She traced over a set of carved symbols.

"It says 'ran into a friend of yours, and they told me I'm not enough of a bad influence on you.' Who'd she mean?"

The Doctor read through the rest of the inscription, written in the ancient language of the Isenal. In the middle was a glyph that didn't translate, a pictogram that resembled a pirate's sailing ship.

"Oh!"

"What is it?"

For a moment, the Doctor didn't answer, sitting back on her heels.

"That's not a glyph, and it's not part of my language either. It's a TARDIS."

Serene looked at the carved ship again.

"That's a TARDIS?"

"I… I had a friend, sort of, another Time Lord, called themselves the Corsair. Their TARDIS looked like a sailing ship, whenever it could. But they died. Not in the Time War. They were killed by - it's a long story."

"And they were here? With River?"

"Looks like. Maybe they came to steal something too. Wouldn't put it past them."

The Doctor's thoughts whirled. She'd gotten to meet the Corsair again not all that long ago, when she was travelling with Graham, Ryan and Yaz. That should have been a way of saying goodbye to them, but instead of acceptance, she found now that it had made the desire to see another Time Lord again even stronger.

Of course, the Master having destroyed Gallifrey in-between…

"Missing River is one thing, but I can't… we have to try and get to the right time."

She got up, hurrying back to the TARDIS. Serene followed, confused.

"But... if the glyphs were carved because you missed each other, and we go back and undo that, wouldn't that create a paradox?"

"Yep."

The Doctor's expression was difficult to read. She was clearly holding a lot back, and Serene knew her friend was probably hurting, but she had to push it this time.

"Doctor, talk to me. What's going on?"

The Doctor reached the TARDIS, but the door wouldn't open.

"Oh, come on, don't start!"

The Doctor rattled the doors, which remained stubbornly shut. She hunted through her pockets until she found the key, but that made no difference either.

"She knows what I want to do, and she's putting her foot down," the Doctor said to Serene as she put the key away again, taking out the sonic instead.

"Doctor… I know this must be hard for you, but-"

"Yeah?"

Serene had never seen her friend like this before, and it unsettled her.

"Doctor, stop! If the TARDIS is trying to prevent you crossing your own timeline, then maybe she's right."

"Maybe she is. But I can't just let this go. I _can't_."

The Doctor began to try opening the TARDIS door with the sonic, ignoring the psychic complaints from her ship. She knew full well what complications could arise from what she wanted to do, but she didn't care.

_'Out of everyone I've ever lost, who do I most want to see again? My family, my friends? River is family, and the last time I saw her was on Darillium, and then she went to the Library and died. And the Corsair? They were even more of an adventurer than me, another Time Lord who didn't believe non-interference was a good idea, to a fault. To be so close and miss them both…' _

The TARDIS still wouldn't budge, but Serene noticed the ruins had begun to shake, just a little but enough to be noticed. A ground tremor? She vaguely remembered reading that seismic activity across Rhyolae was under control in this time period, but that didn't mean there were no quakes at all.

"Doctor? Is that natural, or are we causing that?"

The Doctor paused, turning to look over at where Serene was pointing. One of the tallest pillars was shaking, dust falling down. It continued to do so even after she turned off the sonic.

"Not sure."

"We didn't get permission to come here. We should be careful-"

The Doctor sighed heavily, leaning back against the TARDIS door, head dropping down.

"I know. I _know_. I just…"

She looked up again, subdued.

"Fine. Let's go."

But the tremors were getting stronger and Serene saw the air begin to shimmer.

"Doctor… this is getting really strange."

She stepped away from the TARDIS, turning a full circle to take in everything that was happening. And then she vanished.

"Oh, what now?"

Exasperated, the Doctor took a reading with the sonic of the space Serene had disappeared from. It didn't make a great deal of sense, but the Doctor remembered what Serene had said about the Keepers and how they protected the ruins.

"Booby traps. Was that a teleport?"

She sighed again.

"Usually I'd be more than happy to jump into trouble among booby trapped ancient alien ruins. Not really in the mood right now. But it's not like you're leaving me much choice, are you?" she announced aloud. Maybe it was directed at the Keepers, or the TARDIS, or just the universe in general.

"Suppose this is as good a distraction as any."

She stepped into the space Serene had vacated, and she vanished as well.

The pair of them reappeared together, seemingly in the same place they had left, but with a few noticeable differences, mainly that the stepped temple had vanished, the Confluence was narrower, the walls taller - and there was no TARDIS.

Both women span around, confused.

"So, you studied these people," the Doctor said. "What sort of booby traps did they build?"

"Um, they're actually quite secretive about that. I can see why, now. I thought you said you'd been here before?"

"When they were still building the temples. Any trap with a teleport element, or whatever just happened, was way beyond their capabilities then."

"The Keepers are pretty advanced. I think -" Serene frowned, concentrating. "My memories are a bit foggy."

She tried to access the back-up on the wrist part of her recall device.

"Should I be worried this isn't working?"

The Doctor leaned over, tapping a few controls, then tried her sonic, which refused to work either.

"There must be some kind of dampening field, affecting all electronics."

She licked a finger, holding it up as if to test the wind.

"Yeah… some kind of suppression. Not just electronics. It feels… closed in."

She shivered.

_'Never liked being locked up,'_ she thought. _'But if there's a chance of escape, then I can cope, so focus on that, yeah?'_

"I feel that too," Serene replied. She looked up at the sky, which was the same shade of lilac, looked almost real, but not quite. It was cooler, the orange sun close to setting. There was a brightness, a shininess to everything, a veneer.

"Is this real, do you think? It's not an illusion?"

"Not sure." The Doctor thought about it. "Best to assume it's very real. The important question is, if this is a trap built to catch tomb robbers, is it a prison, or is it likely to be lethal?"

Serene was uneasy.

"I'm not sure. I never thought to research that, back in the Order. I know the Keepers take trespassing very seriously."

"I know River doesn't. She probably found a way around them, or maybe she actually got a permit this time. But anyway-" The Doctor pulled herself together. "If there was a way in, then there must be a way out. So let's have a shufti round, yeah?"

They explored. The walls were high and solidly built, but once Serene gave the Doctor a boost, she managed to get to the top, using creepers as hand and foot holds, careful of the thorns. These ones didn't try and eat them - the Doctor explained that Venandi plants only hunted when they were in flower, using the blooms to draw in potential victims, but they tended to be dormant otherwise.

"Maybe these ones aren't really alive?" she mused, halfway up the wall, prodding a vine. "Another thing to puzzle out."

"Can you see anything?" Serene asked, as the Doctor reached the top.

"Uh, no. Literally nothing."

"What do you mean?"

"Just a grey nothing. Like this section of the ruins are in the middle of a cloud, or a really thick mist. Reminds me of the time I went to Edinburgh Castle."

The Doctor stood up on the top of the wall, and tried to see as far as she could, in all directions.

"Looks like wherever we are, this section of the ruins is the only thing that exists. Not even the temple, from the real world. Nothing with an inside, or a cover."

She picked a loose stone off the top of the wall and dropped it down on the far side, watching it vanish into the 'mist'. There was no sound of it hitting anything, so she threw another, further out into the nothing. Again, no sound, no impact.

"There's gravity, but I can't tell if it works properly out there. Maybe if we go further along, we might see something different?" the Doctor said.

She scrambled down and they continued exploring.

The Doctor still couldn't get any readings from the sonic, so they went old school, investigating by poking everything to see if it was real, or the same as real. They soon discovered they could no longer read the Isenal inscriptions, which really worried the Doctor.

"We're either a really long way from the TARDIS, or we're in some kind of dimensional pocket, something that can be sealed off."

"How come we can still understand each other?" Serene asked.

"I don't always need the TARDIS to translate for us. We got tangled up the day we met, remember? That makes it easier to keep a low-level psychic connection whenever I need to."

Serene considered this.

"Does that mean you can read my mind?"

"I could. It'd take a physical connection, and I wouldn't do it unless you wanted me to. But translating's mostly subconscious."

"Okay. I was just wondering if we were actually dead."

"Not as far as I can tell, no. D'you think that's an option?"

Serene shrugged, trying to appear casual, unworried.

"I don't know. But there's that feeling again. Something in the air. Something not right."

"Like there's no one else around, not at all?" the Doctor replied, trying to put the sensation into words. "Like we're cut off. Might be intentional. Or another sign we're in a pocket dimension."

They went on.

And on.

And on.

"I know these ruins cover a lot of ground, but shouldn't they be a bit more varied?" the Doctor asked.

Serene examined a nearby pillar more closely.

"These are the same inscriptions as before. I can't translate them anymore, but I do recognise them."

"So… either we've been this way before and got turned around somehow, or whatever we're in is repeating, like some kind of cheap copy," the Doctor wondered. "I don't think we can get out over the wall, and there's nothing to say there's an end to this path either."

"If that's true…" Serene thought it over. "Then that's a very effective trap."

"The question comes up again - are we being kept here until the Keepers come and get us, like a holding cell, or are we just stuck here?" the Doctor replied. "And if we are stuck here, how long can we stay alive?"

"Do you think there's danger here?" Serene asked, eyes widening. "Other than being stuck, I mean."

She looked at the creepers growing over the walls. The severed part around her ankle hadn't released itself yet.

"Maybe," the Doctor replied. "Sometimes it's best to assume the worst, but hope for the best."

"And it's not like you ever let a bad situation stop you," Serene pointed out.

"Never."

The Doctor found she was, perversely, beginning to enjoy herself. Yes, being stuck was frustrating, but it was also a puzzle to solve, and that was distracting her from thinking about River, or the Corsair.

"So… let's test this out. If we are circling around somehow, then we should leave a few markers."

She dug a piece of chalk out of her pockets and wrote 'been here before' on the wall, with an arrow underneath, pointing in the direction they were going. Then they walked on, leaving more messages as they went. Serene made sure to check the inscriptions on the pillars too; there was some variation, but they repeated too.

"It looks like this is meant to be a copy of the ruins, but not an exact one. Like a cut and paste version. I keep expecting to find a clue or something, but I don't remember ever hearing of anyone who escaped a trap. Though I suppose the Keepers wouldn't want to advertise it if they did."

"Here's hoping whoever built this has a sense of fair play, or likes to build back doors in, or something," the Doctor replied.

She tapped on the wall, hoping it would perhaps be hollow.

"There must be a way out, somehow."

They advanced slowly, testing parts of the wall, searching for anything that might be out of the ordinary, like a secret lever that would open a hidden door.

"Sorry if this is a bad thing to ask," Serene spoke up, after a while. "But is there anything River would do differently, if she was here instead of me?"

The Doctor paused, thinking about it while trying not to be distracted by how much she missed her sometimes-wife.

"She'd probably have shot something. If her gun worked inside the dampening field."

Serene absorbed that silently. So River carried a gun, and the Doctor was okay with that? Interesting.

The Doctor saw the look on her friend's face.

"Yeah, we had words about that, many times. Much as I hate to admit it, sometimes guns have their uses, especially with the kind of trouble River liked to attract."

"So, how would she have gotten out of here?" Serene asked.

"With some style, I imagine. She'd have made it look effortless, if she could."

"In high heels? I learned early on how hard it is to do that." Serene kicked out her flat boots, much more comfortable and practical, as was her usual outfit of a loose-fitted dress over leggings.

"I'm probably not much help here though," she continued. "I did all that reading about the Isenal and I can't think of anything that'll get us out of here."

"Something'll pop up, keep at it," the Doctor said, reassuringly. "You've been pretty good so far."

"Have I? I feel mostly useless."

"D'you know, in thousands of years, I don't think I've ever travelled with anyone who was actually useless."

"Sometimes I forget that. The thousands of years old bit."

"I wouldn't say I feel it, most of the time. But what does that say - I've been around so much longer than you, and I can't think of a way out yet. So come on. Not useless. Never useless."

They went on.

Serene couldn't shake the feeling that they weren't alone.

"Do you feel that as well?" she asked the Doctor.

"Like we're being watched? Yep."

"But is it someone - something - else in the trap, or part of the trap?"

"Suppose we'll find out as we go." The Doctor shrugged. "If they attack us, then they're probably part of the trap?"

"That… isn't all that helpful."

"Hey, I'm working with the same knowledge you are. But tell me, do the shadows on that side look different to you?"

Serene looked where she was pointing. The sun hadn't set any further than when they'd first arrived, but the Doctor was right. The shadows on one side did look different, darker. Sort of…fuller.

"Is something hiding in them?"

"Doesn't look like the shadows themselves are the problem this time, so yeah, I think so."

Serene decided not to ask her to elaborate on 'the shadows themselves' being the problem. Another question for another time.

"What should we do?"

"Not sure. Keep walking, and see what happens."

"How is that different to what we've been doing already?"

"Oi! I'm working on it."

The Doctor flipped through her mental index of monsters and strange, dangerous things.

_'What can hide in shadows so well, they don't show up at all? Not Vashda Nerada, not in something like this, not enough food for them. Something that doesn't hold a solid shape or can shift…'_

She felt the familiar mix of fear and excitement - something could be dangerous, might try and kill them, but could also be something completely new, something she'd never seen before. Something built specifically for the trap?

"What do you know about the animals on this planet?" she asked Serene. "Specifically predators, anything that hunts."

Her friend thought about it.

"There's a number of large cat-like animals on this continent, but they either hunt on the plains, or leap down from treetops, so they probably wouldn't be here in the ruins. Lots of venomous snakes and reptiles in the jungle…"

"What about nocturnal predators, something that uses the shadows?"

"Not that I know of… but there is a mythology about magic-users that could create sentient shadow creatures called the Scyava, to devour their enemies. One of the rulers of old raised a whole army of them to defend the city from attack."

"This city?" The Doctor asked, putting two and two together.

"Oh." Serene caught up. "Yes. I hadn't thought of that. It makes sense that the Keepers might use that myth, if they were creating some sort of defence mechanism."

She glanced around, taking in how many shadows there were now, from the walls and the standing columns.

"Maybe they wanted to make extra sure that no-one ever got out of the trap."

"That's a cheery thought," the Doctor replied, but she seemed brighter than before.

"Are you _enjoying_ this?" Serene asked.

"Little bit." The Doctor smiled. "Took me a while to get into it, but come on? A trap that's impossible to get out of, potentially filled with deadly monsters? Must be my birthday."

"When is your birthday?"

It had only just occurred to Serene to ask that.

"How would you even know, travelling in time? Does the TARDIS know?"

"Honestly? I just pick a day when I feel like celebrating. The TARDIS can record how old I am, if that's what you mean, but years are different lengths on different planets, so it's a bit tricky to be precise otherwise."

"And that's without all the memories you lost," Serene said, without thinking. "Oh-"

"True." The Doctor shrugged, not bothered just then. "Could be any age, as old as the universe itself, maybe. That's actually a nice thought. All those things I could've seen and done, but I get to do 'em all for the first time again."

"I don't know my birthday either," Serene replied, pensive. "I know I was with the Order for nearly twenty years, but no-one knows for sure how old I was when I was left there. It's a safe bet that I didn't have a whole other life before that, though."

"Life without mystery'd be pretty boring," the Doctor pointed out. "Maybe you'll get your answers, one day."

"Maybe."

Serene sounded like she didn't know how to feel about that, but she was quickly distracted by something moving in her peripheral vision.

"Doctor?"

"I see it. Stay close to me, and try not to get too near the walls."

"Is there only one of them, or an army, do you think?"

"Hopefully not a whole army. My enthusiasm only goes so far."

They threaded their way through the ruins, avoiding the lengthening shadows as best they could. The Doctor noticed that the creepers were more dense in one spot and that, unlike the others, they were flowering, the only Venandi blooms she'd seen in the trap.

"I've got an idea, but it's a bit risky."

"When have your plans ever not been?" Serene asked, but she found she was excited as well as scared. After all, she'd wanted to explore the Isenal ruins, and what could be a more authentic experience than surviving a trap built to protect them? Before meeting the Doctor, such a thought wouldn't have occurred to her, but it was kind of wonderful to experience life in such an unexpected way. Most of the time.

They stopped, turned their backs to the blooms and waited for their pursuer to reveal themselves. Serene tried to ignore the sensation that the Venandi creepers were moving closer - the piece around her ankle still hadn't let go. If these were like the ones outside the trap, then they were probably considering her and the Doctor like they were dinner.

Although the sun didn't move, the shadow lengthened, and took shape. It wasn't a creature that was black in colour, it was like it was made of the shadow itself. It held a shape, upright and humanoid, but it was fluid, and even when it was still, it looked like it was moving, flowing.

"Is that what Scyava look like?" the Doctor asked.

"It's hard to say," Serene replied. "The pictures of them are just… voids. They don't have a set shape. But I'd say that's what we're looking at, yes."

Another shape joined the first, then another, a trio of shadow facing them.

"The myths say anything about how to survive, or defeat them?"

"Um, no. The stories about them were written by those they were defending; there wasn't anyone who needed to defeat them that wasn't on the wrong side. So to speak."

"Any clues?"

The shapes flowed towards them, faces forming in the liquid shadow that were mostly teeth and hunger. Serene thought hard, trying to concentrate though the back of her neck prickled, expecting the Venandi creepers to wrap around her any second, if the Scyava didn't get them first.

"Directing a bright light onto them maybe? Or somehow trapping them in one shape? The records were a bit vague about what they are, how they work."

"Here's hoping then… Wait until I move, then run. Okay?"

"Okay."

They stood still, watching the Scyava flow closer, until they were within pouncing distance. A liquid shape couldn't tense, but there was a sense of preparing themselves for attack.

"Doctor?"

Serene felt her nerves strain with the effort of remaining still, one predator in front of them and another behind, both slinking closer and only her trust in the Doctor preventing her from bolting. The faces that weren't really faces smiled at their prey.

The Doctor took Serene's hand.

"Wait. We need to time this _exactly_ right…"


	2. Chapter 2

At the very last second, the Doctor leapt to the side, pulling Serene with her, just as the Scyava sprang forward.

Missing their quarry by inches, the shadow creatures hit the wall behind, landing among the Venandi creepers. As the Doctor had been hoping, this bloom didn't know what was prey and what was also part of the trap, and it immediately whipped its thorned vines around all three Scyava.

The Doctor, glancing back over her shoulder as they ran, witnessed the Scyava trying to escape the clutches of the creepers by shifting their shapes, but this Venandi was built purely to catch and to kill, and it wasn't giving up that easily, wrapping more and more strands around the three Scyava, engulfing them.

"Hopefully that'll hold them for a while. And put them off hunting us again."

They slowed down, and when the Scyava didn't reappear, nor did anything else leap out at them, the Doctor and Serene resumed their search for anything they hadn't seen before, until they both started to wonder if the trap was literally endless.

And then, on the wall alongside the Isenal inscriptions, was the Doctor's first handwritten chalk message.

The two women stared at it.

"Well, that answers that question," the Doctor said.

"We're caught in a loop?" Serene asked.

"Must be. Question is, how does it work, and how do we break out?"

They both thought that over.

"What do you think is on the other side of the wall?" Serene asked. "You said there was nothing, but what if we tried to climb over?"

"We don't know if there's anything there at all," the Doctor warned. "No way of telling how dangerous that could be."

Serene shrugged.

"Nothing ventured, nothing gained, I suppose?"

The Doctor grinned.

"I was hoping you'd say that."

They gathered together the longest creepers - this Venandi had no flowers, and didn't react to them at all - and twisted them together to make a rope, blunting the thorns with loose stones as they went. The vines were rooted deeply into the ground, but long enough to be swung up and over the other side. Then they both climbed up to the top of the wall, the Doctor tying the makeshift rope around her waist.

"Let's hope this one really is dormant. Getting eaten by a plant halfway down a wall'd be dead embarrassing."

Serene held the 'rope' taut as the Doctor began to abseil down the far side. She paused as she got to the mist, reaching out to pass her hand through it.

"That's weird. It feels like nothing at all. Not cold, not damp, not anything. Like it's not really there."

She slowly descended further, the mist swallowing her up.

"Doctor?" Serene called. "Are you all right?"

"Yeah. It's still like nothing. Though I feel…" she trailed off, unnerving Serene.

"Doctor? Keep talking, I can't see you."

"I feel sort of… distant. It's harder to think… like the dampening field, but for a person…"

Her voice was faint, like she was very far away, or falling asleep.

"Should I pull you back up?"

"I'm gonna keep going… if I stop, or you can't hear me any more, then try and get me back up. "

Serene leaned further over, squinting into the grey mist, still seeing nothing at all.

The Doctor's voice drifted up to her.

"The rope's running out… if there's a floor, it must be further down on this side of the wall - wait, the vines are letting go of me."

Alarmed, Serene began to tug on the rope, which suddenly felt much heavier than just the Doctor's weight.

"No, let it! I can climb further down, hold on…"

But as she spoke, the wall started to shake. Serene dropped to her knees, trying to steady herself.

"Doctor, do you feel that too? The tremor?"

"There's a vibration through the rope, just a bit."

"It's getting really strong, more than before. I think it's reacting to you."

Serene tried to maintain her grip on the rope, to use it to steady herself as well as keep in contact with the Doctor.

"I've reached the end of the rope. There's still nothing."

"Please come back up!" Serene called. "It feels like the walls are going to come down!"

She started to haul the Doctor back up, struggling as the weight continued to increase impossibly.

"Wonder what'd happen if I let go?" the Doctor mused, somewhat dreamily.

Then the tremor turned to a violent quake, the rope snapped and they both fell.

Serene was thrown from the top of the wall, landing heavily on the ground back inside the Confluence. Dazed, it took a moment for her to realise, scrambling to her feet.

"Doctor! Doctor, are you all right? Where are you?"

"Up here."

Her voice sounded further away, and as Serene looked up, she realised why. Above her, in place of the lilac sky, was a reflection of the ruins she stood in. No, not a reflection, because there was the Doctor, upside down, waving at her.

"What? How-?"

Serene looked down at her feet, around at the ruins, then back up at the sky. Nope, still no sky, still a mirror of what surrounded her. The walls reached up until they met the 'other' walls, enclosing the ruins - or what looked like the ruins.

"I don't understand."

"Well, for a start, there really is nothing on the other side, so we can't get out that way," the Doctor called to her. "When I fell, I landed here."

"But where are you?"

"Still in the trap, just a different spot. It's not just a loop; it's a Möbius strip."

"A what?"

"A two-dimensional compact manifold. A non orientable surface."

Serene heard the words, but was no more enlightened.

"What?"

"Try throwing something up to me."

"How can I throw something up there?"

"Just try it."

Serene looked around. The end of the creeper wrapped around her ankle had finally dropped off as she fell, so she picked it up and threw it in the air, expecting it to come back down. But it didn't. Instead it continued up into the air, landing at the Doctor's feet, far above Serene's head, making her dizzy and disorientated.

"Are you upside down or am I?"

"Neither of us are…hang on. I'll show you. Wait there."

The Doctor jogged off along the path, to Serene's right, and disappeared from view.

After a while, the Doctor reappeared at the same level as Serene, the correct way up again.

"I still don't understand."

"Basically, imagine a long thin strip, folded into a loop with a twist in it, like an infinity symbol. That's what we're standing on now, that's why we keep coming back to the same spot. It only has one surface, but because it - and us - are three dimensional, it can be experienced from multiple perspectives."

Serene looked up, still utterly confused. She could still see the 'upside down', although it was fuzzy now the Doctor no longer stood there, the false sky showing through.

"So… an infinity loop. That means there isn't a way out?"

"Not that we can find by walking along. We'll just keep looping around."

"So can we-" Serene struggled to get her head around the concept. "Unfurl it? Make it flat, so instead of a loop, it's just one side with two ends?"

"Nice idea, but I'm a bit stuck on the how."

The Doctor took out the sonic, shook it, tried again to get a reading but got nothing. She started thinking out loud, trying to figure it out.

"There shouldn't really be walls if this is a Möbius strip, it shouldn't have edges like that. The trap is the loop, but the loop is the only thing that exists inside the trap, so the walls must be part of the containment. That's why when I fell outside, it brought me back in. How did the Keepers build this? There must be something generating everything; the loop itself and the dampening field."

Serene wondered what was going on inside her friend's head. Even absorbing some of her memories hadn't helped her understand how the Doctor's mind worked, and she knew she'd never be able to understand. But she could try and keep up.

"Is there a join, or something? A place where the loop starts, or where it repeats?"

"Yes and no. Technically, no, because it's an infinite loop with only one side. We created a starting point for ourselves -" she pointed at the chalk writing on the wall - "so we can mark a full loop and recognise that we've covered all the ground there is. What we need to do is turn that into what you're talking about. Create a join, or a weak spot, make it intersect with outside."

"Okay." Serene tried to think about this. "How?"

"No idea. If I could use the sonic… so what we really need to do is disturb the dampening field first."

She jumped up and down a few times, then picked up a stone and threw it in the air. It came back down at her feet, the 'upside down' part of the trap vanishing into sky.

"Hmm. I don't think it's artificial gravity, more like the loop moved underneath us when we walked, but when we were at separate points of the trap, two parts existed together. There wasn't really an upside down, but we could see it that way. We need to split it again and test it out."

"Test what out?"

"When we were at different points, we could kind of see it as a loop, rather than flat. I think I might be able to use that to break us out, or at least to stop the loop keeping us inside."

"I'm really not following," Serene replied, still somewhat bewildered by the whole situation. "But okay? What do you need me to do?"

"Just stay here for a minute, and keep looking up a the sky."

While Serene did that, the Doctor scrambled up the wall again, and jumped 'out', disappearing into the mist. As Serene watched the sky, it flickered and vanished, replaced by the 'upside down' once more, as the Doctor landed in what was, to Serene, the sky.

"So now…" the Doctor called down. "We jump again."

"Both of us?"

That alarmed Serene; she hadn't been anticipating that the Doctor wanted her to leap blindly into nothing so she could land in the sky. 'Nothing ventured, nothing gained' was all very well, but this was a bit beyond anything she'd imagined when she'd said that.

"Yes. I don't know what's maintaining the loop, but it's probably not designed to keep multiple people in. Here's hoping it won't be able to cope with us both jumping at the same time, from two different points."

"So… you're hoping that if we confuse it enough, it'll break?" Serene asked.

The upside-down Doctor shrugged.

"Pretty much. I could explain it better, but there isn't much to work with here."

Serene sighed, and began to climb the wall.

_'At least you're never bored, travelling with the Doctor,'_ she thought. _'Whatever happens, never bored.'_

The two women stood on top of their section of wall, looking up at each other, seemingly upside down to the other but nonetheless on the same surface.

"Keep looking at me as you jump, if you can," the Doctor called. "When I say go-"

They prepared themselves. Serene took a deep breath, held it.

"Go!"

The Doctor and Serene jumped, vanishing into the mist. The Doctor was right, Serene just had time to realise; it felt like nothing. She was aware of the sensation of falling, of the mist swallowing them up, and then she landed on the ground, at a completely different spot to the one she'd left, as did the Doctor.

"Look up!" the Doctor shouted, and suddenly it was like being inside an MC Escher painting as the loop tried to show four perspectives at the same time of something that only had one side. The Doctor tried the sonic again, and -

"Yes!"

The sky, which was currently other sections of ground, cracked open and the Doctor tried to get a foothold, now the dampening field was fritzing.

"Not the first time I've been stuck in something like this. Should be a piece of cake, unrolling a Möbius strip. Just need to make sure we're on the right side when it flattens out..."

She could do the calculations easily enough, but the sonic wasn't powerful enough to reach all points of the trap, so she focused on creating a weak point, from which she could cut the loop.

"Is it working?" Serene asked, getting carefully to her feet. She wasn't entirely sure which way was up, as it looked like there were four 'ups', all looking down on the others and the ground didn't feel steady beneath her. She couldn't shake the idea that she could fall off the ground and into the sky. Not that there was any sky.

_'This is more confusing than time travel,'_ she thought.

"Sort of?"

It wasn't going all that smoothly, and the Doctor was trying her best to keep up with what was happening around them.

"It's not as straightforward as I thought it'd be. The Keepers weren't messing about when they built this trap."

"What does that mean?"

"It means… hang onto something!"

One final burst, which should have broken whatever was holding the loop together…

Everything expanded, like lungs filling with air, and the Doctor felt something shift, dimensionally. She could sense the mass changing, the properties of the trap altering. Then there was a snap, a sensation of air rushing inward, and everything closed in.

She and Serene were standing next to each other again, on solid ground but it didn't feel like she'd succeeded in unrolling the trap.

"What… what was that?" her friend asked, looking around.

There was only one perspective again, but this time the sky was black and empty, and the stone walls seemed to arch as they reached up, leaning inwards impossibly. Gravity felt wrong, like they were being pushed up and pulled down at the same time and they only just cancelled each other out.

"I'm not sure," the Doctor said. "I don't think that went _quite_ how I wanted it to."

"Meaning..?"

"I think - and this is just a theory - but when I tried to open the trap, instead of unrolling the Möbius strip, I split it in two."

This was not enlightening to Serene.

"And?"

"And they didn't completely separate. See, if the edges of two mirror image Möbius strips are joined together in a four-dimensional space, it creates a Klein bottle."

"Fourth dimension? I thought we couldn't see in four dimensions?"

"I can. Sometimes. Sort of. Think that's where I went wrong. It's… complicated." The Doctor sounded apologetic.

Serene tried, and failed, to understand what was happening.

"Complicated is something of an understatement."

"It's still a surface with one side, like the strip, but where a Möbius strip has a boundary, a Klein bottle doesn't and it can't exist in three-dimensional space without intersecting with itself."

Serene stared back at her, clearly not following any of what the Doctor was saying.

"But what does that _mean?_ Where are we?"

"We're still in the trap. Only now, I've added time as a dimension, so it can't be unravelled without-"

"Stop, stop, stop! I don't know what any of that means! I never studied geometry past absolute basics and this is making my eyes hurt!"

"Your eyes?"

"Oh, I don't know!" Serene sat down and covered her face with her hands. "Just looking at it makes me feel like I'm going to fall over, or fall off, or something."

The Doctor sighed, and sat down next to her.

"Think of it as a bottle with a long thin neck that bends back inside the main body of the bottle."

"Okay?"

"But the inside and the outside are the same surface, like the Möbius strip. So it can't contain anything inside it, because the inside and the outside are the same surface?"

Serene groaned.

"This is worse than trying to understand the TARDIS' dimensions."

"It's actually more straightforward-"

"That doesn't help!"

"Serene."

Habit kicked in, and the former lay sister of the Cerebral Order, reminded of the meaning of the name given to her, took a long, slow breath, in and out. She sat up straight, hands in her lap as if she was preparing to meditate.

"Okay. That doesn't mean I like it when someone does that, but it does work. Sometimes."

"Sorry. This must be frustrating. But I'll find a way out, I promise."

"So long as I don't have to understand it," Serene replied, managing to keep calm by ignoring how nonsensical everything seemed. "Just tell me what to do."

"I'm still working on that. If I can make it intersect, to pass through itself, that'll pull it back into three-dimensional space at least."

"And?"

"And then I can work on getting us out. But with time as a factor, it gets more complicated."

The Doctor tried the sonic again, and this time it buzzed to life right away.

"Ooh! The dampening field's gone! Something went right, at least."

Serene tested her recall device.

"It's sluggish, but it's working. I'll see what I can find on the Isenal, and the Keepers."

"Great. I'll have a wander, see what I can see. Keep an eye out for the Scyava though; Don't know if they're still in here with us, but they probably are."

Technically, it still looked like the ruins, but the dimensions were wrong. The Doctor could sense the way it flowed in on itself in a way that couldn't, technically, be seen, a four-dimensional object. Was this something the Keepers had built into the trap, or had she done this herself? Surely it'd need a lot of power to convert a Möbius strip into a Klein bottle? How was this being generated in the first place? Assuming it was physically real… no, it had to be, somehow.

_'Imagine if River and the Corsair were here too. They obviously avoided this trap, or I'd know about it. Not the sort of thing River wouldn't mention. And having another Time Lord here…'_

That wasn't fair. Serene was doing her best, and it wasn't like most of the friends she'd known before would've been better, especially those from Earth.

_'Maybe Liz Shaw. Zoe would've had fun with this. Ace would've blown something up - oh, she and River would get on like a house on fire, excuse the pun. If it's maths we're talking, then Adric would've been able to sort this, maybe Nyssa would've understood it but the three of us'd probably have argued for hours before getting anything done.'_

She shook herself.

_'Getting caught up in memories, Doctor. Maybe it's the trap, maybe you've just been doing this too long. Too many lost friends. Come on, concentrate. You have a friend, and she needs you.'_

Serene's comment about the TARDIS dimensions was ringing some sort of bell, but she couldn't quite put it together yet. If she had the TARDIS, then the time element wouldn't be a problem, and getting out of the loop would probably be possible too.

So… what if, instead of trying to break out of the trap, she brought the TARDIS inside it? It wasn't like she had a remote control, but she was telepathically linked to the ship. The connection between her and the ship had been blocked, leaving them unable to so much as use the translation circuits, but now the dampening field was gone, she no longer felt as isolated as she had before. The 'something in the air, something not right,' had mostly gone, the trap no longer as closed in and oppressive.

And she had the sonic working too, so there was a chance, maybe? A start at least, something to work with.

The Doctor continued to wander, testing boundaries and feeling out the dimensions of the trap, taking readings with the sonic. It wasn't clear, but they appeared to be occupying the same space as when they'd arrived, but parallel, so pocket dimension was pretty close. A bubble of space/time, separate from the rest of the universe. If the Keepers meant to leave trespassers in it, then the trap was basically intended to kill them, because anyone else would definitely be stuck.

The sonic wasn't powerful enough to break them out, so trying to connect with the TARDIS was looking like the best option.

She went back to Serene, who was still sitting cross-legged on the ground, reading through her studies of the Isenal culture.

"There's a lot here, but little of it's relevant," her friend greeted her. "And, um, this is you, right?"

She projected an image from her device; a similar picture to the one the Doctor had found on the stone column, before the trap had sprung.

"Past me, yeah."

"I thought I recognised you. Them. Whatever word applies. So all those years reading about the Isenal and their deities, and now I'm travelling with one of them?"

Serene sounded amused.

"That isn't something I ever imagined."

"If it means anything, I never meant to be taken for a god," the Doctor confessed, with a smile.

"Does that happen a lot?"

"More than I'd like to admit. Not for a while, so maybe I've broken that habit?"

"Every time I think I've got you figured…" Serene replied, grinning. "You're impossible."

"And if I can get us out of here, I'll believe that. On that note… I've got an idea, but it's gonna be a bit weird."

Serene raised her eyebrows.

"Yes, because everything that's happened in here so far has been completely normal?"

"Good point. But I need your help again."

Serene glanced up at the blackened sky.

"So long as I don't have to jump off any more walls..."

"It's a bit unconventional, but I'm gonna try and connect with the TARDIS. She won't like it, a TARDIS isn't designed to be accessed this way, but I'm hoping she'll make an exception. I already broke most of those rules the last time I had to fix her."

"What do you need me to do?"

The Doctor indicated the recall device.

"That's synced with the TARDIS, as is my sonic, and the both of us are telepathically linked to her. The dampening field's gone too - have you noticed it doesn't feel so closed off anymore?"

Serene realised that was true.

"So I'm gonna try using all of that together to access her remotely," the Doctor continued.

Serene absorbed that, thoughtfully.

"How likely is that to work?"

"No idea. Never tried to do anything like this before, but there's not really any other option. I thought about trying to 'flatten' the Klein bottle, but there's no way of telling what side we'd end up on and that could be disastrous. So I'm trying to remove the fourth-dimension element."

"Okay?"

Serene clearly didn't comprehend what the Doctor was proposing, but seemed happy enough to go along with it. The Doctor knelt before her, made an adjustment to Serene's memory implant with the sonic, then programmed the sonic to connect with the TARDIS, if it could, setting it down in her lap.

"Think about being inside the TARDIS, of your connection with her. Concentrate on just that, empty your mind of anything else. Trust me?"

"I do, yes, but asking me that makes it hard to only think about being in the TARDIS…"

Serene took a slow breath in and out, closing her eyes. The Doctor pressed her fingertips to Serene's temples, closing her own eyes as she joined with her friend's mind.

Using Serene's thoughts, her own, the technological connection between the memory implant and the TARDIS, backed up by the telepathic connection between the ship and the two women, the Doctor reached out, as hard as she could.

She knew the TARDIS wasn't far away physically, but if she was in a pocket dimension then the ship might as well have been on the other side of the Universe. But then again, dimensions were no barrier to the Doctor and her beloved ship, and if there was one thing the TARDIS knew, it was how dimensional engineering and time intersected.

_'Nearly got it… there!'_

The Doctor felt the TARDIS object to her contacting the ship this way, but, well, these were strange times.

_'Sorry, mate. You know I wouldn't ever do this if I had a choice. But if you don't, then we could all be stuck.'_

The last time she'd tried anything like this, the TARDIS had manifested as Idris, and the Doctor found herself picturing Idris stood at the controls, coming to save them.

_'Come on, old girl. You were right earlier, stopping me crossing our own timeline, and I'm sorry about that too. This should be nothing to you. I need you.'_

The TARDIS protested, but the Doctor persisted.

_'I know, I know. I'll make it up to you, I promise. Please?'_

The sonic trilled as the connection became corporeal, tangible, and the Doctor concentrated hard. It was difficult to put into words what she was doing, as it had been when trying to fix the schism within the TARDIS, so she focused on the sensation rather than trying to make sense of it, or understand what was really happening. An almost nonsense phrase, 'inside out and outside in' sprang to mind and she felt something click.

Operating a TARDIS telepathically, from inside a separate pocket dimension, should have been impossible. Had it been tried before? Must have been, maybe she could even install a relay or something to make it possible in future?

But the TARDIS really didn't like that idea, and the Doctor forced it away, concentrating on this last action.

_'Sorry. Won't think that again. Please, lovely. Come rescue me?_ '

The sensation that followed was even more indescribable, if that was possible. Dimensions whirled and shifted and the Doctor was glad she and Serene had their eyes closed, because she dreaded to think what the trap looked like right then. It expanded, contracted, and the Doctor could feel time both freezing and speeding by simultaneously.

_'Nearly there, come on, just a little more…'_

Serene was struggling to keep her concentration, experiencing things she couldn't even imagine, let alone understand, her brain not built to comprehend what was happening around them. For a moment, it felt as if she couldn't breathe, immeasurable pressure on her and her head felt as if it would split open. She tried her hardest to remain calm.

_'Imagine you're safe in the TARDIS,'_ she told herself. _'Everything's okay, it's okay, it's all right-'_

She heard the familiar wheezing, groaning noise of the TARDIS materialising and her heart leapt. Was that real or imagined?

And then there was a sound like a balloon bursting, and everything stopped.

Serene realised she was holding her breath, and let it out, not yet daring to open her eyes. The Doctor withdrew the mental connection between them.

"Is it over?" Serene asked. "Did it work?"

They both opened their eyes, enormously relieved to find that they were, in reality, back in the TARDIS console room, sat on the floor.

"I think so."

The Doctor leapt to her feet, immediately making checks at the console, pushing buttons and flipping switches. Then she ran to the doors and opened them.

The TARDIS was in the same spot they'd left it, and everything seemed to be fine. She took a reading from the sonic, stepping through the doors and back into the ruins.

Serene was afraid to follow. That sensation of immense pressure had been horrible, and she wasn't convinced that the experience of it 'popping' had been real.

"Doctor?"

She got up, and she could see her friend outside, taking more readings and looking around.

"I think we did it."

The Doctor came back in, grinning.

"The TARDIS materialised around us, bringing us back here, out of the trap."

She threw her arms around one of the columns, gave it a big smacking kiss.

"My brilliant ship! Best ship in the Universe!

Serene laughed with relief.

"I think she managed to bring the whole trap in too," the Doctor continued.

"What?"

"She moved the whole pocket dimension we were in, separated us from it and returned us here, then she took the whole thing, the Klein bottle and she put it away somewhere inside herself."

"How? No, wait, don't answer that."

"Not sure I fully understand it myself."

The Doctor went back to the console.

"But yep, there it is. Better close that section off, don't want anyone accidentally wandering in and getting stuck, or anything inside getting out, if the Scyava and the Venandi came in too. And I don't want to risk it flipping and trapping the TARDIS inside it either."

The console beeped and trilled, and the Doctor pulled a conciliatory face.

"No, I know you'd never let that happen. I'm just saying-"

She was interrupted by a shrill noise, and held up her hands.

"Sorry! Didn't mean to offend you. You know we couldn't have gotten out without you."

_'The ship rescued us, and now the Doctor's talking to it,'_ Serene thought. _'My concept of 'possible' and 'normal' will never be the same again. Not that it has been since I met her.'_

But nonetheless, she put her hand on the nearest column and expressed an unspoken thanks to the TARDIS. She'd grown fond of the ship, in the time she'd been travelling within it, and it was impossible not to see her as something alive and sentient, rather than just a vessel. She'd tried communing with the ship when she meditated, many times, but now she felt she'd truly seen the real TARDIS.

The Doctor was still carrying out actions on the console, so Serene went over to the doors and looked outside.

"Is it safe to go out?"

"Not sure. That one trap's gone, but there could be others."

Serene remembered what she'd read about the Keepers, and how seriously they took their job of protecting the ruined city of Laniyah. There was still no one about, but that didn't mean they weren't being monitored, somehow.

"Probably, yes. That's a shame. I really wanted to have a proper look around."

"Might be best to save that for another time. We'll go through the proper channels, get permission and make an outing of it, yeah?"

Serene accepted that, given their experiences that day, that was probably the best idea.

"Okay. Um…"

The Doctor looked up at her friend's hesitant tone.

"You alright?"

"That's what I was going to ask you. Before the trap, you were… upset. About missing seeing River, and your friend."

The Doctor stilled, and Serene couldn't tell read her expression.

"Yeah. I was."

"Is - is there somewhere else we could go? To find either of them?"

"No. They're both dead. Have been for a long time."

"But, aren't they both time travellers? There must be somewhere you could find them that didn't involve crossing your own timeline, or something?

"It's complicated."

Serene had never heard the Doctor sound so defeated, and her heart ached for her friend. Never having had family herself, she didn't really know what it was like to lose someone you loved. She went over to the Doctor and put her hand over her friend's, where it rested on the dematerialisation lever.

"Whatever you need, I'm here."

There was a pause.

"Thank you."

The Doctor turned her hand over, squeezing Serene's.

"I… I don't usually like to look back. I know that sounds weird, seeing as how often I travel backwards in time, but I-"

She scrubbed her free hand over her eyes.

"It's hard. Keeping on looking forward is what keeps me going."

Serene said nothing, just stood beside her in silent support.

"We could go to the Library, I suppose?" the Doctor said, eventually.

"Well, you know I've always wanted to go there," Serene replied. "But-"

"That's where River is. Where she died. I managed to upload her consciousness to the computer hard drive. She's inside the Library."

"Oh."

Serene didn't know what to say to that.

"I haven't been to see her there, since. I don't know if it'll - if she'll be the same. I imagine her there, and she's happy. What would she think if I turned up in her afterlife?"

"I can't answer that," Serene said quietly. "There's only one way to know."

"Yeah."

There was another pause. Then the Doctor pushed down the lever, and the TARDIS faded away from the ruins.

**Notes for the Chapter:**

> I hope this made sense; I don't have a very science-y brain.  
> Next chapter - River!


	3. The Library

The TARDIS materialised in much the same spot as it had the last time the Doctor came to the Library. This time, however, the buildings were teeming with people, as alive and occupied as they should be, no sign of what had happened before.

"Say that again?" Serene asked, as they left the TARDIS.

"The Vashta Nerada swarmed here for a while, then this squad, I dunno what they're called, came in and relocated them to a new planet," the Doctor replied. "Something about threatening the self-destruct, offered them a forest elsewhere... I was a bit too busy last time I was here to try that."

"Okay... I don't remember any of that being in the records I had access to. It must've been an enormous undertaking, clearing all of them out."

"Probably," the Doctor agreed. "Anyway, feel free to wander. I don't know how long I'll be, but we can stay as long as you like. I upgraded your whatsit-" she indicated Serene's recall device "-so we can stay in touch, if we need to."

"Will that work, where you're going?" Serene asked.

The Doctor had been a bit vague about what she was going to do, and Serene didn't like to ask too many questions. River's consciousness had been saved by a neural relay within a previous sonic screwdriver, that much Serene understood, and then River had been uploaded to the main data core. Beyond that, she didn't really know, but then River was no more to her than a few glimpses, unintentionally taken from the Doctor's mind when they connected, and pictures on the wall of the room in the TARDIS where the Doctor had backed up some of her memories.

"I reckon so, yeah," the Doctor replied. "It'll be able to signal me, if there's trouble."

"I can always come back to the TARDIS, if I need to," Serene said, hoping to sound reassuring.

"And if you need anything-"

"I know," the Doctor said. "Thank you."

Serene watched her friend go, hoping she would be okay. Then she allowed herself to feel the excitement she'd been holding back. She was finally in the Library! She'd wanted to visit since she was a child, and now she could finally explore, that was exactly what she was going to do.

The Doctor made her way down through the Library.

_'Why is this so hard? I want to see her, I do, even though she's only a data ghost here. This isn't like Trenzalore.'_

Which was the last time they'd met, from River's perspective. They'd said goodbye then, but the Doctor wasn't that person anymore, nor was she the same Doctor that River had spent so much time with on Darillium.

_'Will she even know me?'_

But those were excuses.

_'Come on, Doctor. Man up. Or, woman up. Person up? Whatever. Get on with it.'_

Connecting herself with the world created in the hard drive wasn't all that difficult. The Library - CAL, Charlotte, whatever and whoever you wanted to call it - recognised her, and let her in, but she knew the staff might be a bit more difficult to deal with, so she was careful not to trip any securities, not wanting to be interrupted.

The Doctor manifested within the virtual world, outside the big house with the beautiful garden and it immediately felt real. No, not real, not quite, but not artificial either. It felt… comforting. This was a happy place, or that was how it was created, anyway.

A gentle cough behind her, and she turned to see Dr Moon.

"Can I help you?" he asked and the Doctor smiled.

"Hello, Dr Moon. Been a while."

"Have we met before?" His tone was soft, but she knew the AI was assessing her, to see if she was a threat to the data core, to the Library, to the people saved here.

"Oh yes. I came here with my friend Donna. And about, 4022 other people?"

Dr Moon processed this.

"Doctor?"

"Yes. I've come for a visit."

His demeanour changed, defences lowering.

"Welcome back, Doctor. You'll find everyone down by the lake. They're having a picnic."

"Thank you."

Rather than skipping straight to the lakeside by thinking herself there, the Doctor walked, taking her time.

_'They? Of course.'_

There were other occupants of this virtual world; CAL had saved the rest of River's team who'd died in the Library. She could hear children playing, laughing.

_'Charlotte. Did she make herself some friends, too?'_

She rounded the corner, and the parkland spread out before her, elegant and tranquil. Anita and one of the Daves were boating on the lake while the others played on the shore, but River didn't seem to be with them.

Shading her eyes against the bright sunshine, the Doctor looked around, and there, under the shade of a tree, was her wife.

River was sat on a blanket, the remains of the picnic around her as she read a book, occasionally lifting her gaze to watch the children frolic in the shallows of the water. She looked relaxed, content and radiantly beautiful.

For a moment, the Doctor didn't move. Just seeing River was enough to make her catch her breath, and while part of her wanted to run to her wife, hurl herself into her arms, another part wondered for the thousandth time if this was a bad idea.

_'When did I get so unsure? You need to not only be yourself, but be the person she deserves.'_

Slowly, she approached. River didn't seem to have noticed her, absorbed in her reading.

_'Should've thought of an opening line. Too late now.'_

"Good book?"

River looked up, startled by an unfamiliar voice.

"Hello. I didn't realise we were expecting a new arrival. Charlotte or Dr Moon usually lets us know if anyone else is here."

"I spoke to Dr Moon. He said you were here."

River looked her over, and there was no sign of recognition on her face.

"And are you visiting, or here to stay?"

Now it was the Doctor's turn to be surprised. There were others uploaded? Others visited?

"Does that happen often? Visitors?"

"Sometimes. Mr Lux has been known to drop by every now and then, to see his aunt."

River looked over at Charlotte, who was splashing Miss Evangelista and shrieking with delight, and smiled in a maternal fashion.

"He may come here permanently, when he passes. He's not necessarily one for libraries, but there are worse ways to spend an afterlife, don't you think?"

"I'm glad to hear you say that."

"Oh? Why is that?"

River got to her feet, taking off her sunglasses to better look over the strange woman before her and the Doctor decided she didn't want to play games, or try and see how long it would take River to work out who she was.

"Cos like you say, a peaceful afterlife isn't for everyone, Professor Song. Don't you miss all the adventures you used to have, across all of time and space? The Byzantium? The Pandorica? That time you wanted to kill Hitler? Our picnic at Asgard? I know I'd miss it."

River gasped, and despite not wanting to play games, the Doctor was pleased that she'd been able to surprise River.

"Doctor?"

"Hello, sweetie."

And just like that, there was no awkwardness, and the Doctor's worries vanished. River saw her, immediately. She'd never met this incarnation before, didn't know she existed, but River still 'recognised' the Doctor.

"Doctor!"

River reached out and grabbed both of the Doctor's hands, squeezing them tight, then they both threw their arms around the other and embraced.

"I missed you," the Doctor murmured into River's hair.

"Of course you did."

They held each other, and for a blissful moment, the Doctor felt nothing but pure happiness. She'd loved a lot of people in her long life, but River was different.

Eventually, they drew back, still holding hands.

"Well… this is new," River said. She looked the Doctor over for a third time, slower this time, taking in the new face, the new body. The Doctor wondered if she was blushing.

"And unexpected."

"Me being here, or just me?" The Doctor asked.

"Yes."

But River was smiling.

"When have you come from?"

"I just left the ruins of the Isenal city, Laniyah."

"Oh."

River hadn't expected that answer.

"I wondered why you didn't turn up."

"I got the co-ordinates, but when I got there you'd already left. Twice, at least."

"You found my messages?"

"Yes."

There was a pause.

"You met the Corsair?"

River looked a little abashed.

"Well, he was a poor substitute for you, my love. But it turns out a swashbuckling Byronic hero can be rather fun when you're running around ancient ruins. We explored almost the whole of Laniyah. I gave some very well received talks at Luna University about the Isenal afterwards. He was very helpful when it came to taking-"

"Souvenirs?"

The Doctor raised her eyebrows, making air quotes with her fingers, but River mirrored her expression.

"Pictures. Even I'm not so foolhardy as to risk stealing directly from the Isenal ruins. The Keepers are very protective."

"Yeah, I found out how seriously they take trespassing the hard way."

"Ah. Yes. My fault, I'm afraid."

The Doctor shrugged.

"It's okay. We got out of the trap."

River noted the 'we' but didn't mention it.

"Of course you did. There isn't a trap built that can hold you."

They both smiled.

"I wonder how we missed each other, though? And why the message went to you rather than…any of the other yous."

The Doctor shrugged.

"No idea. Hiccup in the timestream, maybe. Glad you managed to cope without me."

River took the Doctor's hands again, squeezed them.

"There's no need for jealousy, my love. The Corsair may be the type one runs around with for a little fun, but they certainly aren't the type you bring home to meet the parents."

"Not in the order we did that, no. So you didn't marry him or anything?"

"No, I did not! I may have married other people, Doctor, but you were the only one I ever really loved."

Suddenly serious, River put one hand to the Doctor's face and for a moment they were both still, looking into each other's eyes.

"Tell me you know that," River said, finally, not asking whether the Doctor felt the same about her. She knew she held no claim on the millennia-old alien with the multiple lives and faces. Usually she preferred to flirt and tease, to be playful but here, now, after her death, what was the point?

In reply, the Doctor leaned in and kissed her.

It was a gentle kiss, and in some ways, their first. The Doctor was in a new body, and River no longer had a physical form, but it was still very real to them both.

Eventually, they drew back.

"Hello, wife," said the Doctor.

"Hello, wife," River replied.

Hand in hand, they walked away from the lake.

"Who are the other two children?" The Doctor asked. "Did Charlotte create some friends?"

River seemed a little surprised she didn't know.

"They're the children Donna had, when she was saved here, Ella and Joshua. Didn't she tell you about them?"

"Oh! Yes, she did, I just didn't know they were still here. They never really existed, after all."

"They were always real to Charlotte. And they're real to me."

"Of course."

The Doctor thought about that.

"Would they want to know about their half-siblings, in the outside world? Or would that complicate things?"

"Why don't you tell me about them?"

As they walked, the Doctor told her all about what Donna had been up to, since the Doctor had had to leave her behind. River already knew about that part, but she was pleased to learn about Donna's husband and their children, details the Doctor had not shared before. And then the Doctor told her about what she herself had been up to, since Darillium. The places she'd been, the things she'd done, the friends she'd made, and lost.

Remembering the way her 'fam' had reacted to Captain Jack, knowing they'd probably have been the same with River, she didn't yet mention them. It was too recent, too raw. She had Serene as a friend now, but still, losing the first people she'd met on regenerating had been more painful than she liked to admit.

"You'd have loved Bill. In fact, you'd probably have tried to run off with her, and she probably would've gone with you. I wonder if I'll ever see her again."

"Does that help? Knowing that even after she died, she's out among the stars, like Clara?"

The Doctor winced. It hurt to be reminded of how many people had died travelling with her, because of her.

"Sometimes. Does it help knowing that Amy and Rory lived a full life together and died of old age, even if you didn't get to be with them for it?"

River was quiet for a moment. She didn't mention that she had, in fact, visited her parents many times since they'd been sent back in time. The 'lock' around New York city may have meant the Ponds couldn't leave, but it didn't mean their time-travelling daughter couldn't drop in later. She'd been at both their deathbeds, alongside her adopted brother, Anthony. They'd organised both their parents' funerals and River had found herself putting up the gravestone that had caused the paradox in the first place. But she could never tell the Doctor any of that.

"Is it better than the alternative, do you mean?" she asked. "Like getting to live on here, instead of just dying?"

"Yeah."

"When you've seen as much of the Universe as we have, a quiet end to a life seems preferable, doesn't it? I got to live a life full of adventure, right up to the last minute. I was never boring, and now…"

River turned to look back at the lake, the trees, the peaceful calm of their surroundings.

"Now this is enough. If you'd asked me when I was alive, I wouldn't ever have chosen this, but you can't run forever. And what could be better than here? I can access anything in the Library. Even I couldn't have read everything in the Library while I was alive. Now there's time."

"I… I'm sorry I didn't come here before."

"I didn't expect you to. I wasn't always happy about that, but I've come to terms with it all."

The Doctor remembered overhearing River tell Clara about that.

_'Left me like a book on a shelf,'_ River had said. That had never been the Doctor's intention, but that didn't mean it wasn't true.

"Guess I was always hoping I'd get to see you again, out there."

"You still might. The universe can be so unpredictable."

"Is this where you say 'spoilers' and give me that infuriating look?" the Doctor asked.

River smiled, but she said nothing.

They walked on, around the full circumference of the lake, talking all the while. The Doctor had been extremely hesitant to talk about the Master's revelations about her past, but if she could talk to anyone, surely it was River?

"Do you believe him?"

"I don't know. Some of it feels true, and the Matrix… it plays tricks but I don't think even he could've created something so convincing from nothing. And the rage in him, that's real."

But River was thinking of something rather different.

"So there are more of you, out there in space and time?"

"Looks like."

"Goodness."

The Doctor didn't want to know what River was imagining at that precise moment.

"I never thought I'd know everything about you," River continued. "But that is _quite_ the revelation."

"Yep. Still trying to process it myself."

"If it is true, even partly-" River paused. "Then that makes you even more impossible and wonderful than ever. So I believe it. If anyone in the whole of the Universe could be all that, and all I know of you besides, then it would be the Doctor."

The Doctor ducked her head.

"Knew there was a reason I married you."

"That wasn't flattery, my love. The Universe needs you, always has."

"What keeps me going is thinking of the future, not my past."

"Maybe they're the same thing. You'll find out what you need to know of your past in the future. And if you don't, then maybe you never needed to know."

The Doctor thought that over.

"That's one way of looking at it."

"You know that life isn't a straight line, any more than time is. I'm not saying ignore everything he said, but I am saying don't waste time worrying over it, if there's nothing you can do about it."

"Mm. I tried a few things to see if I could recover any memories, but got nothing. Since then, I've been trying to do what you're suggesting. If Serene can live without knowing who she is, where she comes from, then so can I."

"Serene's who you're travelling with now?" River asked.

"Yes. I met her in the Cerebral Order. She's upstairs now, exploring the Library."

"I'm glad you're not travelling alone. It was nice to have you to myself, but you don't do well without someone beside you."

River said this without a trace of jealousy, having grown used to the Doctor having many friends and learned not to resent them. She'd befriended many of them herself, looked in on some of those who'd parted ways with the Doctor, helped them out when they needed it, and never said a word to the Doctor about any of it.

"I know. We've been good for each other, I think."

They walked a little more, in silence.

"Is there anything you need?" The Doctor asked, suddenly. "Anything I can bring you here, or create within the data core?"

"Not really. You could check with Dr Moon, see if there's anything that needs to be repaired, or upgraded, but we can create anything we need here. Charlotte - CAL, she might not have built it, but she can control everything."

They'd reached the picnic blanket under the tree once more, and River picked up the book she'd been reading. The Doctor saw River's diary was there too.

"Is that from your memories, or..?"

"The real one's in the Library. It's in private storage though, library patrons can't access it. Not just for my sake; you're in it a lot too, and that shouldn't be public knowledge."

This time the Doctor knew she was blushing. She'd never read River's diary, and not just because 'spoilers.'

"Nice to know it's been preserved though. If I'd known at the time who you were, all the things that would happen, I'd have made sure to've kept it."

At some point after River's death, Nardole had the diary in his possession, but the Doctor didn't know exactly when it had come from, or indeed where it was now.

"That was the strangest thing about that day," River replied. "You didn't know me, not at all. Until I said your name, I was just another person you met. And I couldn't talk to you about us, because that would change everything. But even without really knowing me, you were so sad when-"

She broke off. It was so strange to talk of your own death, after the fact.

"When you saved the lives of 4025 people?" the Doctor asked. "There should be a commemorative plaque in the Library for you at least. Maybe I'll get them to put one up."

But River wasn't listening. She looked down at her feet, took a deep breath, then looked back up at the Doctor.

"And that's why you shouldn't come back here."

"What?"

The Doctor had never expected to hear that, and it hurt.

"Why?"

"Because as you said, what keeps you going is thinking of the future, not the past."

The Doctor opened her mouth to protest, but River carried on, not letting her speak.

"And by coming here, you're looking back, thinking about what you've lost, when you should be looking forward. That's who the Doctor is, what you need to do, what the Universe needs you to do. Run, Doctor, to whatever needs you, and stop looking back."

The Doctor said nothing. River put her hand to the Doctor's face, her eyes betraying her emotions.

"I'm not saying forget me, or forget your past. But remembering is one thing, and if you spend too much time looking over your shoulder, who knows what you'll miss? Someone who needs you to save them, or to stop them."

The Doctor knew what she was saying was probably true, but she didn't want to admit it.

"The Library is a safe haven. I will always be here if you need me, I promise you that. But this isn't like Stormcage. You can't take me out skating on my birthday and pop me back before I'm missed."

"I know that."

"The time we spent together… that was wonderful. But like I said, you can't run forever. I've stopped running, Doctor, but that doesn't mean you should."

"Never!"

The Doctor pushed aside her sadness, and smiled.

"The Corsair said you weren't enough of a bad influence on me, ey? Look at you now."

"My days of stealing artefacts are behind me, Doctor."

"I thought you said you didn't take anything from Laniyah?"

River smiled her knowing smile.

"I said I wasn't going to risk stealing from the Isenal ruins and enraging the Keepers. I didn't say anything about not 'borrowing' from the museums. And that little heist was all the Corsair."

The Doctor's smile broadened.

"I might've known you'd make good partners-in-crime. I'm amazed the universe survived."

"Much the same could be said about you and him. The Corsair told me about the time the two of you liberated a dozen barrels of wine from the cellars of the Magnate of Beyjir? That must've been some party."

The Doctor laughed.

"I'd forgotten about that. Probably because of how much of that wine we ended up drinking."

They walked back to the house, where the others were setting the table for dinner.

"Are you sure there's nothing you need?" the Doctor asked, suddenly awkward again.

"I'm fine. I'll admit to the occasional urge to run off and steal something, or get into trouble, but I did plenty of that while I was alive. Give my love to the universe?"

River leaned in and kissed her again. The Doctor made an effort to capture the moment.

One last, perfect kiss.

River drew back.

"Goodbye, wife," she said.

"Goodbye, wife."

The Doctor watched River turn and go into the house, then she withdrew her consciousness from the data core.

The Doctor opened her eyes and found herself sitting on the floor, where she'd plugged herself in. There was no one around, but the knowledge that, this time, there were thousands of people, safely and happily going about their lives inside the Library made her feel less alone. That one of them was her best friend helped too. Serene had plenty to keep her busy, so the Doctor could stay where she was a little longer, thinking over her visit with River. There was no rush to get back.

There was time. There was always time.

**Notes for the Chapter:**

> There will be another 'special guest star' in the next chapter :)


	4. Chapter 4

Serene had spent hours just wandering the Library, browsing and exploring. Eventually, she found a table in a quiet corner nook, and settled down to read her way through the stack of books she'd picked out. One of them was a history of the Library itself, and she flipped through it until she found the part the Doctor had played, and that of River Song.

It was rather vague, and reading between the lines Serene could guess this was down to Strackman Lux, the only survivor other than the Doctor and Donna Noble, being part of the family that built the Library, and that they probably wanted to present the most media-friendly version of events. But it did mention that Professor Song had led the expedition to begin reclaiming the Library from what turned out to be a swarm of Vashta Nerada, and made allusions to her sacrificing herself to rescue the people who'd been uploaded. No wonder the Doctor wouldn't tell her the full account. Serene hadn't gotten her head around the timelines the Doctor and River traversed, but that didn't really matter.

_"She was a time traveller too,"_ the Doctor had said. _"She died on the day I met her."_

Serene felt a little uncomfortable looking up any more details of a day that clearly still hurt her best friend to remember, so she shut the book and turned instead to a weighty tome of comparative mythology.

"Excuse me, dear."

Serene looked up from her book at the woman who'd spoken.

"But we haven't met before, have we?"

Serene was puzzled.

"No. I've not been to the Library before."

"I don't just mean here. I travel quite widely."

The woman smiled and Serene couldn't decide if her overly friendly matter was genuinely unsettling or if she herself was overreacting. She closed the book, putting it on the table in front of her.

"Do you?" the woman continued.

"Do I what?"

"Travel."

"Why are you asking me that?"

"You… look like you travel. There's a certain look people get when they travel, especially as widely and in as unlimited a fashion as I do. It's not common, and I've become quite good at spotting it."

Serene looked the woman over more closely. She had pale white skin, dark hair piled up on top of her head and was dressed in a rather peculiar fashion - a long skirt and fitted jacket in purple, over a blouse, held closed at the throat by a cameo brooch. Not the sort of clothes Serene expected someone to choose to visit a Library, although some of the academics who'd visited the Order had been eccentric dressers.

The woman sat down in the next chair, leaning over and putting her hand over Serene's.

"You're not from Earth, though."

Serene's discomfort became alarm, although she couldn't say why. This place was supposed to be safe, secure. There shouldn't be danger here, but this woman was making her more than uneasy.

"They're usually from Earth. Recently, anyway. So predictable. But then here you are."

Serene drew her hand back from the strange woman, activating her recall device. She didn't want to disturb the Doctor unless it was important, but her instincts were telling her this could be.

"I wouldn't do that if I were you, dear."

The woman's tone sharpened, her hand grabbing Serene's arm, holding it still.

"There's thousands of people inside the Library. How many are you prepared to let die?"

Alarm turned to genuine fear and Serene froze. The Library as a whole was full of people, true, but no-one was close by. No-one to help, but that meant no-one to get hurt either, not right away.

Among the memories of all the people, the creatures that the Doctor had warned her about, tiny flashes lit up in her head, the remains from when the Doctor's memories had surged into Serene's brain, into the recall device and she had instantly gained more knowledge than she could ever process in a lifetime. Almost all of them were gone, erased, removed. But sometimes, Serene found she knew things.

"Missy. You're Missy."

The woman's smile turned to one of absolute delight.

"He told you about me? How wonderful!"

Serene stared back at her. Fear remained, but there was a sensation of standing on stronger ground. She didn't know what was happening, but she wasn't totally in the dark, which was what the other woman wanted.

"He?"

Missy's expression flickered. The darkness hiding underneath her eccentric attitude had already shown itself, but what peeked out now was pure chaos.

"Excuse me, dear?"

"We're talking about the Doctor?"

"Who else?"

Serene couldn't help herself. She let herself smile a little, knowing it wasn't safe to provoke this - person - but doing it anyway.

"She -" Serene lingered over the word. "Has never told me anything about you. I absorbed some of her memories."

For a moment, nothing. Then Missy smiled enormously, theatrically and Serene wondered what the other woman was thinking. Probably not what she was going to say.

"She? Well, I suppose that was inevitable, really."

Missy indicated herself.

"I always was something of a trend-setter. A trail blazer, you might say. Is this the first time she's been a woman? She got the idea from me, of course."

"I doubt it."

"And what would you know?"

Missy's hand snapped tight around Serene's arm, painfully.

"You're just the latest pet who follows her around, like Mary's Little Lamb. Don't start thinking you're actually anything important."

Serene stared back at her. She was very aware that the threat to the other people in the Library could be very real, but she didn't feel afraid of this woman any more.

"I don't."

"Good. Now we might actually get somewhere."

Missy activated a little control she'd concealed in her other hand, and Serene gasped in pain and shock as something like electricity shot through her. It paralysed her, and she could just perceive something form around her, like a bubble.

"Much as killing you might be fun - can you imagine her face if she came back here and found you dead! What larks!"

Missy giggled.

"This won't actually do you any real harm. It's just a containment field. I could use it to kill you, I suppose. If I were to, I don't know, remove all the oxygen from inside it, for example."

She manipulated the control and did just that. Missy leaned forward, looking into Serene's eyes, watching with interest as Serene, still unable to move, began to suffocate. Panic returned, but Serene couldn't shake the sensation of disbelief. This didn't seem real, she didn't feel like she was about to die.

After perhaps twenty seconds, Missy pressed the button again, and the oxygen returned.

"My friend does sometimes find interesting people to travel with. Maybe it's because you're not human. The previous pets have mostly been human, and while I wouldn't say they're not fun, they can be a bit… limited. Have you been travelling with her long?"

Serene concentrated on breathing slowly, trying to ignore what had just happened.

"Long enough that you're not surprised to learn she has enemies, at least," Missy continued, answering her own question.

"And I'm not the first to hurt you either, so that's a lesson already learned, too."

"What do you want?" Serene managed.

"From you? Nothing really. I just wanted to know if you actually were what you looked like. It's something of a matter of pride, being able to spot them."

"Spot what?"

"I've already said; the Doctor's little pets."

"I'm not a 'pet'. I'm her friend."

"Po-tay-to, to-mah-to." Missy rolled her eyes.

"Whatever you are, you can be really quite conspicuous you know. She can't always recognise me, and it seems I haven't met every version of her yet either, but when I see someone who's travelled with the Doctor, it's very obvious that's what you are."

"Then why-?" Serene wanted to gesture at the field holding her, but couldn't move. She flicked her gaze up and down, hoping that would suffice.

"Everyone needs a hobby, dear. But I didn't actually come here with any particular scheme in mind, and it seems I'm rather fond of this place, now it's no longer swarming with ravenous shadow bugs."

"So it's a coincidence, you being here at the same time as us?"

"Well, it's almost surprising our paths haven't crossed here before. It's a big universe, yes, and we're both time travellers, but you have to agree, it's inevitable we'd run into each other sometime."

Missy looked down at Serene's recall device.

"You were going to call her on that? What is it?"

She reached into the containment field, which didn't seem to affect her. That was annoying.

Serene had a strange flash of what life might have been like, if it had been someone like Missy who'd taken her away from her quiet little life in the Order and shown her a different side of the Universe. Trouble either way, but would she still have said yes to travelling, if it was with someone who liked to cause malevolent trouble, rather than trying to help people? She liked to think she would never have gotten involved with anyone like Missy, but she'd been so sheltered back then, before she'd seen anything else of the universe. And without the warning of the Doctor's memories of Missy to let her know what she'd be letting herself in for, would she have been so picky?

It was a troubling thought, given what Serene had discovered about what she herself was capable of.

"Ooh, this is a fun little thing!"

Missy was pressing buttons, playing with the recall device. It wasn't supposed to work when someone else used it, but as it was still attached to Serene, it was responding to Missy, who was scrolling through the index. She quickly worked out how to locate certain stored files and recalled those relating to the Doctor, not reading them but bringing up images of places she and Serene had visited, things they'd seen together. It felt oddly violating, and Serene concentrated on trying to block them. The implant aspect wasn't designed to be thought controlled, but it was connected to her brain physically. If she tried thinking of something else really hard, tried to identify the sensation of the device working, maybe she could block it.

"My, you two have been busy!" Missy sounded delighted.

"So many places… she seems quite different this time. Maybe we could be friends! Gal pals. Gals being pals. We could have sleepovers, and do each other's hair."

Serene shut her eyes, trying as hard as she could to prevent Missy recalling her memories.

"Oh, stop that, you'll strain something," Missy said dismissively. "I could open up your skull and take the memories straight out of your brain, if I really wanted to. Bit messier, though, and I'd rather not. Don't want to ruin my favourite shoes."

She activated a recording of the little projection of the Doctor, sitting back as she took in the picture.

" _This_ is the Doctor?"

Missy sounded disapproving, or at least disappointed.

"She finally becomes a woman, and _that's_ how she chooses to dress? Has she never even _heard_ of tailoring?"

She indicated her own outfit.

"That's it. If we don't end up killing each other, I'll take her shopping. Hair's not completely terrible, though. She's actually quite pretty. What do you think?"

Missy leaned in again.

"You're not one of the ones that fall in love with the Doctor, are you? It's so embarrassing for them when that happens. Trailing after him with puppy-dog eyes, doing everything he asks without question because they want to impress him?"

Serene, noticing the change in pronouns, chose not to ask which of the Doctor's previous friends Missy was talking about, if it was even true. She'd gone back to the memory room in the TARDIS with all the pictures of the people the Doctor remembered, several times, trying to put names to faces. But there were so many of them, and they'd done so many things together. Only to be expected over two thousand or so years really.

And it was a fair question. How did she feel about the Doctor? Serene had never met anyone like her before, didn't even know people like her could exist, outside of fairy tales. (And sometimes within them too). She hadn't really had friends growing up, never grown close to anyone like she had with the Doctor. And you wouldn't hurl yourself into danger on a regular basis for just anyone. But it wasn't a romantic fixation, which seemed to be the question Missy was asking.

"She's my friend. I care about her, but that's all we are."

Missy didn't reply right away, examining Serene closely.

"Interesting. I'm still wondering what her face would look like if I killed you now. Would she be angry? Would she cry? Or would she just add you to the list of people she couldn't save and move on?"

"You keep on acting like I have no idea who she is. Like I'll be shocked and horrified by anything you say."

"Is that what you think?"

Missy's eyes were dangerously fascinating to watch. So many thoughts and expressions whirled behind them. Serene couldn't read most of them, knew Missy was a genuine danger to everyone in the Library but still felt oddly unafraid.

"You did say you'd absorbed some of her memories… would you like some of mine, too?"

That felt like more of a threat than open murder did, surprising Serene.

Missy reached both hands into the containment field to press her fingertips against Serene's temples.

"Shocked and horrified, you said? I can do that."

For one horrible moment, Serene was tempted to give in. What could she learn here? The incident with the Doctor had been unintentional, and the memories that had surfaced had been utterly at random. But no. Curiosity was one thing. This woman could probably kill her with her mind alone, if the urge took her.

Serene screwed up her face, applying every mental blocking technique she'd ever heard of, resisting any way she could.

"Oh, how sweet," Missy exclaimed. "You actually think any of those will do anything at all. By all means, keep trying. It makes it all the more fun."

Serene could physically feel Missy's thoughts touching her own, feel the power of the Time Lady's mind. It wasn't like that with the Doctor, who was respectful and careful, and Serene tried all the harder to push back. She visualised walls surrounding her, shouted nonsense rhymes inside her head to block Missy reading her surface thoughts. But through all that, she could hear Missy laughing, and she knew her attempts had done nothing.

Serene had expected that she'd see the memories replaying inside her head, as if projected, but it wasn't like that. They appeared in her subconscious; she could feel them there but not yet experience them and an almost indescribable sensation ran through her, like she'd been electrocuted.

Missy was still giggling as she withdrew both her mind and her hands, only for this to abruptly stop as something slammed into her.

Serene's eyes flew open to see the Doctor bearing down on both of them.

"Get away from her!"

Missy stood, holding the back of her head.

"You threw a _book_ at me?"

"I mean it, Missy! Don't touch her!"

"A book! No-one's done that since _school!_ No wonder you dress like you do if this is what you're like this time around."

The Doctor used her sonic on the containment field, which popped like a balloon.

Serene leapt to her feet, moving around the table so it was between her and Missy.

"Are you all right?" the Doctor asked her friend.

"I'm fine."

"Sorry, is no-one going to pay any attention to the fact that she threw a book at me?"

Missy sounded aggrieved, but her reaction was almost clownish. Serene looked from her to the Doctor, who was anything but. Her friend was clearly furious, but also conflicted. Serene could only imagine how she was feeling - no doubt already emotional from visiting River, to then immediately be confronted by her 'best enemy'.

"If nothing else," Missy continued. "I'd have thought the librarians'd give you a fine."

"Knowledge is the best weapon there is," the Doctor replied, still holding the sonic out, her whole body visibly tense.

Missy rolled her eyes.

"Oh, lovely. How long've you been holding that retort in your pocket?"

"At least my pockets actually hold stuff."

The Doctor gestured to Missy's jacket, which had the typical fake pockets of so much of women's clothing, no more than a few inches deep.

Missy moved the hand holding the back of her head to over one of her hearts, pretending to gasp in shock.

"Ooof, you found my secret vulnerability. You win this time, Doctor. Defeated me with your superior pockets."

"What are you doing here, Missy?"

"Why, the same thing you are, love. Did you think you were the only one to visit her?"

The Doctor actually staggered in shock, grabbing hold of the back of a chair to hold herself up, stunned speechless.

"Dr Song might be your wife, but I knew her too," Missy continued. There was a vicious little smile on her face and she seemed to be enjoying herself immensely.

"Did she never tell you that? About all the times we met, the little games we played?"

Serene turned to the Doctor with increasing concern. There was a look of great hurt in her friend's eyes,

"She's a lot more fun than you are, I can tell you that for nothing," Missy said. "A lot less worried about right and wrong-"

"D'you want me to throw summat else at you?" the Doctor snapped, cutting her off.

Missy's smile was sharkish.

"Well, it's not like you can hurt me any other way, is it? You have so many weak spots, Doctor. Who can blame me for… probing them?"

Serene, sensing that this could get very bad, very quickly, moved over to the Doctor's side, putting a hand on her raised arm.

"Doctor-"

"D'you know who she is?" The Doctor asked Serene, not taking her eyes off Missy.

"Yes."

"Did she hurt you?"

"I'm all right. Are you?"

There was a moment's pause, then the Doctor lowered her arm.

"I don't know."

Missy was watching them both with amusement.

"It's something I tell you over and over, and I know I'm not the only one. Caring about the little people makes you weak, and it makes you vulnerable."

The Doctor took a breath, calming herself. She couldn't tell exactly what part of Missy's timeline she was crossing here, but it seemed like it was still fairly early in this regeneration. Before there was any notion of redemption, but there was actually less cruelty in her than the Doctor might have expected right then. Not that she'd ever expected to run into this incarnation of the Master again.

Seeing her had snapped the Doctor out of what she'd been feeling after leaving River, but the way she'd reacted to missing the Corsair collided with the surprise of seeing another Time Lord and she felt herself suspended above a whirling mass of emotion.

_'No time for that now,'_ she thought. _'Focus.'_

She put the sonic away, mentally rifling through her pockets in search of something that would help.

"Did you really come here to see River?"

"I did. Even I'm not so completely irredeemable as to start an evil plan in a Library."

The two Time Ladies stared at each other.

"So. We're both women this time around."

"I did it first," Missy pointed out.

"Yeah? Came up with that accent on your own, did you?"

"You didn't invent being Scottish, dear."

"You'd never so much as have visited Earth if it wasn't for me."

"Maybe. Half the fun of killing humans is knowing how annoyed it makes you, I will admit that. But it's their own fault for being so easy to off. Is this one any sturdier?"

She looked over at Serene, who'd retreated a few steps, not wanting to involve herself in their confrontation.

"Finally ran out of humans to trot along after you and started travelling with - what are you, dear?"

"My name is Serene."

"Really? How unfortunate for you. Where did you pick this one up?"

"That is none of your business," Serene replied, living up to her name. It was easy now to have no spite in her tone. Missy didn't really care about her, other than how she connected to the Doctor, and all she herself knew about the relationship between the Doctor and the Master was how complicated it was. Thousands of years of friendship, being enemies, and everything in between.

"Ooh! You do like them sparky, don't you? Every now and then I think maybe I should have a little sidekick, but I'd probably just forget to keep feeding it, or something. Is that what happened to what's-her-name? The short human, the one with the dead boyfriend."

The Doctor gritted her teeth.

"Clara."

"Clara! Of course. Is she dead too?"

How to answer that? Best not to, in case this was before Missy's last encounter with Clara.

Actually, the Doctor realised, Missy shouldn't remember this encounter at all. It wasn't all that unusual to run into someone from an earlier point in their timeline, but the TARDIS was generally pretty good at avoiding complications like this. The Doctor knew she couldn't risk doing or saying anything that might change her own personal past and Missy's future, especially not with someone as mercurial and unpredictable as Missy. Not so much seeing this version of the Doctor, but giving Missy any information about her own future would be dangerous.

By now, Library staff, alerted by raised voices and their internal security sensors, had arrived and were assessing the scene.

"Is everything all right?" one asked, taking in the tension between the three women. Missy gave him a little wave.

"Everything's wonderful, darling. Don't fret, it just gives you wrinkles."

The Doctor sighed, putting her hands into her coat pockets.

"Do you have a TARDIS, Missy? Where is it?"

Missy laughed, a tinkling little sound.

"Are you kicking me out, Doctor? Have you become a librarian? I can see you doing that, you know. Spending your days telling people to shush."

"Do you really want to do this? Here, now?"

There was a moment of strained silence as Missy stared back at her.

Then she shrugged.

"I'm not really in the mood, no. Honestly, it's a bit embarrassing, running into you when I don't have some terribly complex, sinister scheme in motion, and it's actually quite hard to come up with one off the cuff. I suppose everyone needs a day off. So relax. I won't murder half the Library patrons on a whim. Not today."

The staff watched this exchange in confusion.

"Just working things out with the Mrs!" Missy called to them, then turned back to the Doctor. "Oh, wait. You already have a wife, but she's dead and stored in the mainframe. Awkward!"

The Doctor couldn't help but roll her eyes.

"Time you left, then. River won't want to see you just now."

Missy pouted.

"Well, that's no fun. Fine. I promise I'll have a wonderfully diabolical plan ready to go next time we meet."

_'Daleks or Cybermen?'_ the Doctor thought to herself, but not too loud. Didn't want to give Missy any ideas that she might not already be hatching. Odd that she was less worried about this version of the Master than the (to her) more recent version, but then that one had destroyed Gallifrey. Missy had at least gone on to (or rather, would) make steps toward redemption.

The Library staff accepted that there was no situation, and left as Missy smoothed down her skirt, turning and walking away, but the Doctor followed.

"I don't need an escort, dear."

"Course you do."

The Doctor was thinking fast, not wanting to put anyone at risk if Missy proved to be lying, or changed her mind. She had half a plan, which was better than a lot of times, and all she had to do here was get Missy to leave quietly, and stop her remembering this encounter. Should be easier than, say, stopping her taking over a planet. She kept herself positioned in between Missy and Serene, just in case.

"Just making sure you actually do what you say you'll do this time."

Missy ignored this.

"Tell me, are you what the one with the eyebrows regenerated into, or are there more of you?"

_'More of me? Now there's a question,'_ the Doctor thought.

"Why d'you ask?"

"This is clearly the first time you've been a lady, judging by the shoes. Did your entire wardrobe burn down, or are you wearing all that by choice?"

"Oi!"

"At least you finally stopped wearing question marks on everything. That was _so_ embarrassing. Why didn't you just have a big flashing sign over your head with 'I like to be mysterious' on it?"

"Hark who's talking, 'evil Mary Poppins'?" the Doctor retorted.

"How very dare you!" Missy drew herself up, her face a picture of offended.

"This is the height of 'strict Edwardian schoolmarm' chic, I'll have you know! Have you never even _tried_ skirts? So much more fun to swish around in. It's like a cape for your legs."

"Not really me."

"Oh come on, Doctor. Unbend a little, for once. Take the pet shoe shopping, before it dies and you have to get a new one."

"Missy." The Doctor's tone sharpened.

"Fine, fine. I wasn't that bothered about killing her."

Missy winked at Serene, who was keeping a careful distance from her.

"Not this time, anyway."

They turned a corner to find a tall fluted column that didn't quite fit in with the Library architecture.

"Old habits die hard," Missy said, by way of explanation. "Not quite as conspicuous as your silly little blue box, but…"

She opened the hidden door, turning back to blow a kiss.

"Bye, darlings. Don't forget to write! Kill you later!"

The Doctor's hand flashed out, breaking open a tiny vial right in Missy's face. Grey smoke escaped the glass, vanishing into Missy's nose and mouth.

"Wha-?"

The face of her oldest enemy, sometimes-maybe-friend, was a picture of surprise as she unintentionally inhaled the knock out drops, knees buckling instantly.

The Doctor caught her before she fell, dragging her the rest of the way inside the ship.

"Close the door behind me and wait outside," she said to Serene, who stood watching, unsure what was happening and how to react.

"What are you doing?"

"Just… wait outside. Please."

Serene, uncomfortable, did as she was asked, and the Doctor found herself in Missy's TARDIS.

She let Missy's unconscious form slide to the ground and looked around. The console room looked to be a mix between a British sitting room from 1910 and London's Natural History Museum.

There were Doric columns inside as well, leading to an arched ceiling. Scarlet drapes covering the walls and the floor was carpeted. Taxidermied birds under glass cloches leered down from high shelving, and beside the console was a chaise longue and a small table covered in a lace cloth, set out for tea.

"Wow, you really committed to this whole 'psychopathic Edwardian nanny' thing, didn't you?" the Doctor said aloud.

But she didn't have time to linger - there was always the possibility that Missy had set traps inside her TARDIS, in case of intruders. And the Doctor had had enough of traps, for the time being.

Quickly, she knelt by Missy's side, and pressed her fingertips to the other woman's temples. Wiping the memories of another Time Lady was always going to be more difficult - and she wouldn't put it past Missy to set traps in her own head, either - so rather than remove every trace of their meeting, she put a filter over it, so that Missy wouldn't remember that she'd met the Doctor's current incarnation. The memory would be foggy, like a dream, and the Doctor added a little push to stay away from River, at least for a while.

The thought of her enemy befriending (if that was the right word) her wife was almost unbearable, even after seeing River herself. The Doctor knew she didn't have the right to choose who River did and didn't speak to, not even now she was dead, but…

' _If I do come back and see River again, we're having words about the company she keeps,'_ the Doctor thought, withdrawing from Missy's mind. _'The Corsair was one thing, but there should be limits, even for the thoroughly disreputable Dr Song.'_

For a moment, she was tempted to poke about in Missy's TARDIS a bit more. Who knew what nasty little schemes she could prevent from happening, now she had the chance? And the things she could change…

_'I could save Gallifrey. Stop the Master from ever looking in the Matrix, make sure they never find out about the Timeless Child, stop them from burning it all.'_

And if she could connect to this TARDIS telepathically, the way she did her own, then maybe she really could do that. But it wasn't the first time the Doctor had ever been tempted to change things, and she doubted this TARDIS would be any more keen on crossing personal timelines than her own was. She might as well try and change Missy's personality from inside her mind, and that was a definite step too far. Not that it would work; she wasn't even sure how well this memory editing would take.

_'Maybe I'm feeling my age. Haven't felt like that much this regeneration, got a whole new lease of life with this body. Wouldn't say that age brings wisdom, but it does bring experience. I can't wipe away something that big and not expect there to be serious repercussions.'_

And of course if she did prevent the Master learning that particular truth, then she herself would never have learned it either, another paradox. Removing one person's memories so that she, the Doctor, never found out that she had lost so many of her own… Interacting with someone from your own past was tricky enough without trying to change things.

'You've done enough,' she told herself, and she made a swift exit.

Serene was waiting, a little way away.

"What happened?"

"All sorted. You ready to go yet?" The Doctor put on a bright and breezy façade, but Serene didn't move.

"Is she - What did you do?"

The Doctor showed her the empty vial.

"Seda knock out drops. Put a Judoon to sleep, these would."

"Should I be worried you're carrying those around?"

"Forgot I had them. Only picked them up a little while back, when I was going through some cupboards and stuff. Not much different to the stuff you have a formula for on your memory device."

As she put the vial back in her pocket, a thought struck her.

"Ha! I really did defeat her with my superior pockets. The contents of them, anyway."

But Serene still looked concerned, and with good reason, the Doctor realised.

"She'll wake up. I didn't hurt her, I just needed to stop her remembering she'd seen us."

She filled Serene in on where Missy had likely come from, in the Doctor's timeline, as they headed back to the Doctor's TARDIS.

"What happened between the two of you, before I got there?" the Doctor asked.

Serene shrugged.

"Not much. She somehow knew I was your friend. She said she could see it on me. We - talked. Sort of. She threatened to kill a lot of Library patrons, and then she gave me some of her memories."

"What?" The Doctor stopped dead, mouth open in shock. "Why?"

Serene shrugged again.

"I don't know. I think she was showing off, maybe? Like she said, she never travels with anyone, and I think she wanted someone to see how clever she is. That's what she thinks I'm for, anyway."

"She is clever, unfortunately. What memories, exactly?"

_Gallifrey._

The word popped into Serene's head forcefully, Missy's little present making itself known. Not just the things Missy had done, but sharing some of her personal memories, so that someone else had them, like backing up to an external hard drive. But she couldn't tell the Doctor that.

"I'm not sure yet. They're established in my mind, but I can't quite see them. I don't think they're as bad as she threatened, though. It doesn't feel like they're bad."

"I can take them out, if you want. Shouldn't be too hard-"

"No, it's all right. I can cope. If anything happens, we can just do the untangling thing again, right?"

Serene tapped her recall device.

"One thing though… is there any way of locking this properly, so only I can use it? I don't like the idea of anyone else being able to access my memories, unless I want them to. Other than you and the TARDIS, that is."

"I'll give it a go."

They reached the TARDIS, and went inside. The Doctor set the controls, distractedly.

"Are you all right, Doctor? How did it go, with River?"

The Doctor looked up, her expression mixed. Sad, resigned but also less troubled than before.

"It was hard, seeing her like that. I mean, she's dead, but she's still her, still River. It's better than never seeing her at all, but it's not like seeing her for real. And then seeing Missy… I didn't expect to see that incarnation of the Master again."

"It sounds complicated."

"It is. Very."

"Anything I can do?"

The Doctor thought about it.

"Are my clothes really that bad?"

"Um, no. But you do tend to wear the same outfit all the time?"

"Saves time worrying about what to wear. And Missy usually wears the same thing too."

Serene, realising that the Doctor was focusing on a small issue raised by meeting Missy so she didn't have to think about the larger issues, didn't quite know what to say.

"We could go and rummage through the wardrobe again?"

"Nah. Done that already. D'you fancy going shopping? We could try the Millefiori Galleria? It's like a market, but it's as big as a city."

Serene smiled. The Doctor knew she could talk to her about River, about her lost friends and current enemies, whenever she wanted to. No harm in having a little fun in the meantime.

"Sounds great."

And off they went.

* * *

Disclaimer: I got the idea of Missy and River meeting from the Big Finish audios (though I haven't listened to that one yet), same as the reference to the Doctor meeting the Corsair in a previous chapter is a reference to when this happened in the comics. Maybe one day I'll think of a story featuring both of them.

The story of River and the Corsair meeting in the Isenal ruins, will soon be published as a separate story.


End file.
